Terrorist group Boko Haram's offer to exchange some of the kidnapped schoolgirls for prisoners has reportedly been rejected by the Nigerian government.

"I'm not surprised that the Nigerian government refused to negotiate in this manner with Boko Haram," Dr. David Curry, president and CEO of watchdog group Open Doors, told The Christian Post in a phone interview on Tuesday. "I think if the news is true that the girls are still together, I think that's hopeful news. I think many had feared that the girls had been scattered and already sold.

"Our hope at Open Doors is that Boko Haram will release the girls for humanitarian reasons because they are innocents, and so forth. But I don't know if they'll do that. They've shown a callousness toward human life that is shocking to most in the world."

BBC News reported on Monday that the government of President Goodluck Jonathan has turned down Boko Haram's demands, with Interior Minister Abba Moro insisting that the Islamic militants have no moral position to make such an offer.

"As far as this government is concerned, the option of [the] swap of innocent citizens with people who have taken arms against the country ... is not on the table," Moro said.

The schoolgirls, believed to be over 270 in number, most of them Christians, were taken last month from an all-girls school in Chibok, Borno State, after armed Islamic militants stormed in with trucks.

Human rights groups have said they fear many of them have already been raped and are to be sold as brides for the militants.

"We can safely assume that the abducted girls have been raped by their captors, if not worse," Rona Peligal , deputy director for the Africa Division of Human Rights Watch, said last week. "If they return home, they could be traumatized and stigmatized if they are known to be raped, pregnant or with child from their abductors. What happens if they're trafficked would likely pale by comparison."

The international community has reacted with outrage, and the U.S. has decided to send in military forces into Nigeria to help with the search and rescue of the girls, an offer which Jonathan accepted.

Boko Haram released a couple of videos admitting to have carried out the kidnappings. In the most recent video on Monday, many of the girls were shown in a large group.

"It is now four years or five years that you arrested our brethren and they are still in your prison. You are doing many things to them and now you are talking about these girls? We will never release them until after you release our brethren," said Boko Haram leader Abubakar Shekau in the video.

Curry told CP that the news that most of the girls are still together provides a "silver lining in a very dark situation."

Open Doors, which reports on Christian persecution around the globe, lists Nigeria as No. 14 on its list of countries where followers of Christ face the most extreme persecution.

Boko Haram has been waging war on the Nigerian government and Christians in the religiously divided country for close to five years now, killing thousands on an annual basis by blowing up buildings and churches, and attacking schools and congregations.

Curry offered that the reason why Boko Haram's actions are now gaining mainstream attention is because the issue touches different groups in different ways.

"I think many people weren't concerned when Boko Haram was just attacking churches. Now that they're attacking schoolgirls, when there is [the potential] of them being sold into sex trade, I think there are a number of things that have drawn attention to this. It is cutting across many different types of groups that have interest in these kinds of issues," he said.